这是一页术语页（terminology page），给中文读者解决一个具体问题：英文文献里那些词到底对应中文的什么。peptides 译作「肽」或「多肽」，指由氨基酸（amino acid）通过肽键（peptide bond）连成的短链分子；单个单元叫残基（residue），两个残基叫二肽（dipeptide），更多则统称多肽（polypeptide）。这些译名本身没什么难的，难的是它们在网络材料里被混用：peptide、protein、polypeptide 常被不加区分地写成「肽」，于是后面所有的讨论都建立在一个含糊的起点上。我先在这里把起点钉住。
需要说明的是：本页只做术语与阅读方法的科普，不提供任何功效结论（no efficacy claim），不提供人体剂量（no dosing），不推荐任何产品或来源。文献中的发现一律按文献来描述，并注明实验体系；细胞或动物实验的发现不一定能外推到人体结局。想看「作用」这个词的分类可以看多肽的基础作用，想看活性测定的边界可以看多肽活性物质科普，站点总入口在chemyo peptides。
English gloss: this is a terminology page for readers who meet peptide chemistry in english and discuss it in chinese. Peptides translates as tai or duotai and refers to short chains of amino acids joined by peptide bonds; one unit inside a chain is a residue, two residues make a dipeptide, and longer assemblies are called polypeptides. The translations are simple, but the usage online is not: peptide, polypeptide and protein are frequently flattened into a single chinese word, so a discussion that starts from that word starts from something ambiguous. This page fixes the starting point first. It offers no efficacy conclusion, no human dose and no product or source recommendation, and it describes published findings as literature with the model system named.
核心术语的中英对照
第一组是结构类术语。amino acid 是氨基酸，即带有氨基、羧基和侧链（side chain）的小分子；side chain 决定残基之间的差别。peptide bond 是肽键，是一个残基的羧基与下一个残基的氨基缩合脱水形成的酰胺键（amide bond）。sequence 是序列，按惯例从 N 端（N-terminus）写到 C 端（C-terminus），方向本身就是分子身份的一部分：残基相同、顺序相反的 two peptides 是两种不同化合物。conformation 是构象，指这条链在特定溶剂、pH 与温度下采取的形状。
第二组是制备与分析类术语，也是中文材料里最容易含糊的一组。synthesis 是合成，固相合成（solid-phase peptide synthesis）指把生长中的链固定在固相载体上、每步之后洗掉多余试剂的方法。protecting group 是保护基，用来暂时屏蔽会参与副反应的侧链。cleavage 是切割，指把完成的链从载体连接臂上释放下来。purification 是纯化，通常靠反相色谱（reversed-phase chromatography）完成。purity 是纯度，是在某一方法下针对某一批次（lot）的测量结论，不是某个名字永久携带的属性。
English gloss: the first group of terms describes structure. An amino acid is a small molecule carrying an amine group, a carboxyl group and a side chain, and the side chain is what distinguishes one residue from another. A peptide bond is the amide linkage formed when the carboxyl group of one residue condenses with the amine of the next, releasing water in the process. A sequence is written by convention from the N-terminus to the C-terminus, and that direction is part of the identity of the molecule, because two chains with the same residues in reverse order are two different compounds. Conformation is the shape a chain adopts under a stated solvent, pH and temperature. The second group covers preparation and analysis: solid-phase synthesis anchors a growing chain to a support and washes away excess reagent after every cycle, protecting groups mask reactive side chains, cleavage releases the finished chain from its linker, purification is usually chromatographic, and purity is a measurement conclusion about one stated lot under one stated method.
| 中文术语 | english term | 含义要点 |
|---|---|---|
| 多肽 / 肽 | peptides | 氨基酸通过肽键连接而成的短链分子 |
| 氨基酸 | amino acid | 含氨基、羧基与侧链的基本结构单元 |
| 肽键 | peptide bond | 缩合脱水形成的酰胺键，决定主链刚性 |
| 固相合成 | solid-phase synthesis | 链固定在载体上逐步延长，每步洗涤去除多余试剂 |
| 保护基 | protecting group | 暂时屏蔽活性侧链，避免副反应的基团 |
| 纯度 | purity | 某批次在某一方法下的测量结论，非永久属性 |
| 冻干 | lyophilised | 纯化后经冷冻干燥得到的固体粉末形态 |
几个最容易读错的词
第一个是 purity（纯度）。它是一个批次（lot）在一种分析方法下的测量结论：在这一针色谱、这一波长、这一梯度条件下，目标峰占了多大比例。换一种方法、换个实验室，数值可以合法地不同。所以看到纯度数字时，真正要问的是：哪个批次、用什么方法、谁测的、有没有原始图谱。没有这些信息的数字只是一句没说完的话。identity（身份鉴定）也类似：质谱（mass spectrometry）给出的质量数与 proposed 序列相符，并不单独证明序列顺序，通常还要有串联碎裂（fragmentation）的信息来支撑。
第二个是 lyophilised（冻干）。它描述的是形态与处理方式：纯化后的溶液经冷冻干燥变成固体粉末，便于称量与储存。它是一个 handling 与 storage 的类别词，不是质量判断词，也不暗示任何功效。第三个是 assay 与 activity（测定与活性）：这两个词在网络材料里几乎总被翻译成「作用」，但它们指的其实是一次实验及其读数。本页建议保留「测定」这个译法，因为「作用」在中文里太容易被读成效力承诺。相关的层次讨论见化学与生物学交界处。
English gloss: three words do most of the damage in chinese material. Purity is a measurement conclusion about one lot under one analytical method: one injection, one wavelength, one gradient, one laboratory. Change any of those and the number can legitimately change, so the useful questions are which lot, which method, who ran it and whether the raw trace is available. Identity is similar: a mass spectrum gives a mass consistent with a proposed sequence, and on its own it does not prove the order of the residues, which is why tandem fragmentation is normally reported alongside it. Lyophilised describes form and handling, meaning the purified solution was freeze-dried into a powder for weighing and storage, and it is neither a quality grade nor a hint of any effect. Assay and activity are the pair I would most like to see translated as determination rather than action, because action reads as a promise in chinese.
如何读一篇英文的肽类论文
我读这类论文时按固定顺序看四个位置。先看 materials 部分：序列是怎么来的（合成还是分离）、纯度用什么方法确定、有没有给出原始图谱。再看 methods 部分：实验用的是纯化蛋白、细胞裂解液、完整细胞还是动物模型，浓度是多少，对照怎么设。第三看 results 的呈现方式：给的是原始曲线还是归一化后的图，误差棒代表什么，重复了几次。最后看 discussion 里作者自己怎么限定结论，通常负责任的作者会把局限写在那里。
第四个位置最容易被跳过，但往往信息量最大。作者自己写下的 limitation（局限）通常就包含了本页一直强调的边界：体外结果需要体内验证、动物模型不能等同人体、样本量有限、检测方法的灵敏度有下限。跳过这一段直接看结论，是把文献读成口号的最快方式。社区里的二手转述往往连 methods 都不提，我把它单独归档为 anecdote 放在reddit 讨论归档，与文献严格分开。
English gloss: when I read a peptide paper I go through four positions in a fixed order. First the materials section: where the sequence came from, whether it was synthesised or isolated, how purity was determined, and whether raw traces are shown. Second the methods section: whether the experiment used a purified protein, a cell lysate, intact cells or an animal model, what concentration was applied, and what the controls were. Third the results: whether raw curves or normalised plots are shown, what the error bars represent, and how many times the experiment was repeated. Fourth, and most often skipped, the limitations the authors wrote themselves, which is usually where the honest boundary of a paper is printed. Second-hand summaries in forums typically omit all four positions, which is why I file them separately as anecdote rather than as literature.
- 先确认序列来源与纯度测定方法，再去看任何活性或结合的读数。
- 始终记录实验体系：纯化蛋白、细胞还是动物模型，以及浓度与对照设置。
- 把作者自己写的 limitation 当作结论的一部分，而不是可跳过的段落。
- in vitro 与 animal 的发现不一定能外推到人体结局，本页不提供任何功效或剂量信息。
Frequently asked questions
peptides 中文到底叫什么？
肽键和酰胺键是一回事吗？
纯度数字越高就代表越好吗？
冻干（lyophilised）是什么意思？
本页会提供剂量、价格或购买建议吗？
References and public sources
Literature searches and public reference links. None of them confirms or denies any community claim filed elsewhere on this site.